There is a simple answer to why you should concentrate on organic search results rather than PPC advertising:
It's cheaper in the long run.
With PPC, you pay to play. As such, it's a good way for new businesses to get a foothold in search engine rankings. Ideally, though, you won't have to do this forever and you'll have a top ten ranking without ever having to pay for it. That's the dream of every site owner.
You should try to make the dream a reality. One of the problems with PPC advertising is that it becomes a kind of crutch. Overnight you can get a top ten search result for a search.
A great result with relatively little work, just cost. What happens is that site owners rely too heavily on PPC campaigns and don't focus enough energy on organic search results. Imagine if your business was in the top ten of both the sponsored and standard search results: you'll have twice the visibility.
If you have a high ranking via organic search results two things have happened: you have a number of backlinks to your site and your site has been optimized via content for that search phrase. Other things affect search engine rankings, but these are the two basic ones.
The second issue is supremely important because it means you are providing a content-rich site for new web surfers. Content is not just a way to rank high in the search engines but a way to create an impressive site that will inspire repeat visitors. The results are two-fold.
There are some other very important issues at stake. In Google, for one, organic search results are much larger and more immediate than sponsored results, which are off to the side. Web surfers very often look to organic search results first.
The quality of sites using sponsored results is also waning, almost to the point that these sites seem like spam. The longer this continues, the more people will click on organic results before sponsored results.
In the early going, web surfers were not savvy enough to realize that sponsored results were a PPC marketing effort. This is less true today.
The thinking is that if a site lands in the top ten without having to pay for it, they must be the best resource on the topic.
Finally, another issue is that pay-per-click bidding costs are on the rise. It makes just as much sense to hire a content-writing firm to create pages of new content for the site, and optimize that content for search engines, as it does to invest in PPC.